1. Field of the Invention
The invention relates to a filling level transmitter, comprising a sound-conducting tube and a filling level sensor with an ultrasonic transceiver and sensor electronics.
2. Related Art
Such filling level transmitters with an ultrasonic transceiver that generates and outputs ultrasonic waves and receives reflected ultrasonic waves are used to measure filling levels in fuel containers in motor vehicles and are therefore known. In order to protect against the aggressive components in fuels, the sound transmitter and the electronics are arranged outside the fuel container. It is disadvantageous here that for this measurement the wall of the fuel container has to be penetrated, which is problematic owing to the material of the fuel container. It is also known to arrange the transceiver in the fuel container. However, this requires encapsulation of the transceiver, wherein the encapsulation has to be configured such that the sound-outputting region of the transceiver extends into the fuel and only the remaining part of the transceiver is encapsulated. The seal necessary for this gives rise to considerable expenditure for the filling level sensor.